Abstract

Aim:ToassesstheeffectivenessofBacillussubtilisstrainLN8Basabiocollectorforrecoveringpyrite(Py)andchalcopyrite(CPy)inbothseawater (Sw) anddeionizedwater(Dw), andtoexploretheunderlyingadhesionmechanismin thesebioflotationexperiments. MaterialsandMethods:ThebioflotationtestutilizedB.subtilisstrainLN8Basthebiocollectorthroughmicroflotationexperiments.Additionally, frothermethylisobutylcarbinol(MIBC)andconventionalcollectorpotassiumamylxanthate(PAX)wereintroducedinsomeexperiments.Thezeta potential(ZP) andFourier-transforminfrared spectroscopy(FTIR) wasemployedtoexploretheadhesionmechanismofPyandCPyinteracting withthebiocollectorin SwandDw.TheadaptabilityoftheB.subtilisstraintodifferentwatertypesandsalinitieswasassessedthroughgrowth curvesmeasuringopticaldensity.Finally,antibioticsusceptibilitytestswereconductedtoevaluatepotentialrisksofthebiocollector. Results:Superioroutcomeswereobservedin SwwherePyandCPyrecoverywas∼39.3%±7. 7 %and41.1%±5.8%,respectively,without microorganisms’presence.However,B.subtilisLN8BpotentiatePyandCPyrecovery,reaching 72.8%±4.9%and84.6%±1. 5 %,respectively.WhenMIBCwasadded,onlythePyrecoverywasimproved(89.4% ±3.6%),depictinganadverseeffectforCPy(81.8% ±1.1%). ZP measurementsindicated increased mineralsurfacehydrophobicitywhenPyandCPyinteracted withthebiocollectorin bothSwandDw.FTIR revealedthe presenceofprotein-relatedamidepeaks,highlightingthe hydrophobicnatureofthe bacterium.Theadaptabilityofthis strainto diversewatertypesandsalinitieswasassessed,demonstratingremarkable growthversatility.Antibioticsusceptibilitytests indicated that B. subtilisLN8Bwassusceptibleto23ofthe25antibioticsexamined,suggestingit posesminimalenvironmentalrisks. Conclusions:ThestudysubstantiatesthebiotechnologicalpromiseofB.subtilisstrainLN8Basanefficientsulfidecollectorforpromotingcleaner mineralproduction.Thiseffectivenessis attributedtoits abilitytoinduce mineralsurfacehydrophobicity,aresultofthedistinctcharacteristics ofproteinswithinits cellwall.